smear
verb [ T ]
uk/smɪər/ usto tell lies about someone or something in order to harm them:
Accusations of corruption were nothing but a deliberate attempt to smear the company and its management.
smear
noun [ C ]
uk/smɪər/ usa lie that is told about a person or organization in order to harm their reputation:
They dismissed the stories of financial malpractice as an irrelevant smear.